Method and apparatus for the crushing of stone and ore



A. POUPIN Oct. 24, 1944.

METHOD AND APPARATUS FOR THE CRUSHING OF STONE AND ORE Filed Aug. 2, 1939 Patented Oct. 24, 1944 UNITED, STATES PATENT OFF-ICE METHOD AND APPARATUS FOR THE CRUSH- 1 ING OF STONE AND ORE Arthur Poupin, Santiago, Chile Application August 2, 1939, Serial No. 288,058 In Chile May 19, 1939 5 Claims.

mer crushers and ball mills or by incision as in toothed cylinder crushers.

The combination of direct crushing pressure and shearing has rarely been adopted for coarse crushing of stone or ore,'b'ut has been extensively used f-orgrinding operations as may be seen in the old stone grinding mills. It is well known that the resistance to shearing or transverse strength of stoneis but a fraction (a mean of about /7) of its resistance to direct compression, and if both the shearing and compression efforts are combined the resultant effort required for crushing is considerably smaller than ifonly direct compression were applied to the stone. This combination of efforts has been adopted for the crushing operation in the crusher of th present invention.

The present invention for crushing breakable material is based on the principle of the application of resultant slant forces of the aforesaid combined efforts, by means of two crushing heads mounted on parallel shafts, one head hollow with an interior conical or hyperbolical crushing surface and the other head solid with an exterior conical or hyperbolical crushing surface, the solid head being located in the cavity of the other head, the relative positions of the heads being eccentrical one to the other, the conical or hyperbolical crushing surfaces of both heads having the same slant, the heads being mounted on independent revolving shafts, and the crushing of the stone being effected by the approachment during rotation of corresponding parts of the crushing surfaces between which the stone is placed, and the relative motion of said crushing surfaces causing the required pressure and shearing effort on the stone.

In order that the present invention may be clearly understood it will be described here-inbelow in connection with one embodiment illustrated in the accompanying drawing, in which:

stone C placed between the crushing surfaces.

Figure 2 shows in elevation a crusher built according to the invention and Figure 3 is a cross section through (1-1) of Figure 2. 1

Figure 4 is a diagrammatic vertical section through the crushing heads of a modified form of the invention.

Referring now to the diagrammatic drawing of Figure- 1, A and B represent vertical axial sections of the hollow and solid crushing heads respectively of the crusher, both heads being conical in the present example, and the lines FG and HJ are sections of the crushing surfaces in the same vertical plane. C represents a stone submitted to pressure between said sur' faces, the centers of these pressures being at.

E and D. The crushing heads rotate at the same speed and direction and due to their eccentricity the crushing surfaces advance approaching each other and exerting on the stone a force P, which is resolved into a crushing force normal to the surface of the crushing head and a shearing force parallel to said surface, on account of the grip of the crushing surfaces on the stone, will be vertical at the point considered and will always lie in a vertical plane at right angles to the axes of the heads as they rotate. A counter pressure P2 will similarly act at point E in a vertical plane and at a distance d which depends on the angle of the conical surface of the heads, parallel to the plane of pressure PI.

The two forces PI and P2 produce therefore a crushing pressure on the stone at points D and E combined with a transverse straining action i which will materially reduce the power required to crush the stone.

The crusher of the present invention has been designed on the principle above described. Figure 2 illustrates an embodiment of the invention, in which a hollowcrusher head I is fixed to one end of shaft 2 journalled on hearing 3, 3 and a solid crushing head t is fixed to one end of a shaft 5 journalled on bearing 6, 6. The hollow crushing head I has a conical crushing surface 1 and the solid head 4 has a conical crushing surface 8 formed by a smaller cone of the same angle, the solid head being eccentrically located inside the hollow head. 9 and I 0 are belt pulleys on the two shafts which are independently driven, and II', I 2 are flywheels on these shafts. The axes of the shafts and crushing heads are in the same plane and bearings 3 and 6 are bolted to a bed plate I3; suitable hoppers and ducts (not shown) are provided for introducing the material to be crushed into the space I4, between the crushing heads at the top and for receiving the crushed material at the bottom from the narrower space I5 after having been ejected from the crusher by centrifugal force.

Shaft 5 of crushing head 4 has an end bearing [6 which allows a longitudinal play controlled by lever I|resisted by a spring l8. This device permits a certain elastic action to the opening of the crushing surfaces to avoid damage when unbreakable foreign objects are unintentionally admitted and to regulate the opening in harmony with the hardness of the material by the pressure exerted by said spring l8.

Figure 3 is a sectional view of the crushing heads through the line 11-1) of Figure 2, which shows the relative position of these heads, one axis parallel to the other. The conical crushing surfaces may be made plain, toothed or corrugated, depending on the material to be crushed. Alternately these surfaces may be made hyperboloidal. The axes may be horizontal, vertical or inclined to suit the working conditions.

The modification having the hyperboloidal surfaces is shown in Figure 2, wherein crushing head A has a convex hyperboloidal crushing surface 1 adapted to cooperate with the concave hyperboloidal crushing surface 8 of the crushing head B.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I hereby declare that what I claim is:

1. Crushing apparatus comprising two crushing heads mounted on parallel shafts, one head being hollow with an interior crushing surface of conical shape, the other head being solid with an exterior crushing surface of conical shape and being located in the hollow portion of and eccentrically, with relation to said hollow head, the space between the conical surfaces of the heads being greatest at one side where the material to be crushed is introduced and smallest at the opposite side where the crushed material leaves the crusher, bearings for said shafts and means for driving said shafts independently.

2. A crushing apparatus comprising two crushing heads mounted on parallel shafts, one head being hollow with an interior crushing surface of concave hyperbolical shape, the other head being solid with an exterior crushing surface of convex hyperbolical shape, said last named head being located in the hollow portion of and eccentrically with relation to said first named head, the space between the cooperating surfaces of said heads being greatest at one side where the material to be crushed is introduced and smallest at the opposite side where the crushed material leaves the crusher, bearings for said shafts and means for driving said shafts independently.

3. A crushing apparatus as set forth in claim 1 in which a regulating elastic device is provided for one of the driving shafts of the crusher so as to operate yieldingly due to the different hardnesses and sizes of the material being crushed.

4. A crushing apparatus as set forth in claim 2 in which a regulating elastic device is provided for one of the driving shafts of the crusher so as to operate yieldingly due to the different hardnesses and sizes of the material being crushed.

5. A crushing apparatus comprising two crushing heads mounted on parallel shafts, one head being hollow with an interior crushing surface of convex hyperbolical shape, the other head being solid with an exterior crushing surface of concave hyperbolical shape, said last named head being located in the hollow 'portion of and eccentrically with relation to said first named head, the space between the cooperating surfaces of said heads being greatest at one side where the material to be crushed is introduced and smallest at the opposite side where the crushed material leaves the crusher, bearings for said shafts and means for driving said shafts independently.

ARTHUR POUPIN. 

